c++指针作为函数参数 急谢谢

Question

 

Answer 1

题目1代码：

#include <iostream>
using namespace std;

int main()
{
	float a,b,tmp;
	cout << "请输入a 和b的值:"<< endl;
	cin >> a >> b;
	{
		tmp = a;
		a = b;
		b = tmp;
	}
	cout << "交换后a=" << a << ",b=" << b <<endl;
	return 0;
}

题目2代码：

#include <iostream>
using namespace std;
float a,b; //全局变量
void exchange(float a,float b)
{
	float tmp;
	tmp = a;
	a = b;
	b = tmp;
}


int main()
{
	cout << "请输入a 和b的值:"<< endl;
	cin >> a >> b;
	exchange(a,b);
	cout << "交换后a=" << a << ",b=" << b <<endl;
	return 0;
}

题目3代码：

#include <iostream>
using namespace std;

void exchange(float *a,float *b)
{
	float tmp;
	tmp = (*a);
	*a = *b;
	*b = tmp;
}
int main()
{
	float a,b;
	cout << "请输入a 和b的值:"<< endl;
	cin >> a >> b;
	exchange(&a,&b);
	cout << "交换后a=" << a << ",b=" << b <<endl;
	return 0;
}